This section provides background information related to the present disclosure which is not necessarily prior art.
Magnetic clutches are used for selectively transmitting torque between two rotating parts. For example, magnetic clutches are used in vehicles to selectively operate accessories, such as air conditioning compressors, or pumps. Such magnetic clutches typically include a stator, a rotor, and a hub. The stator includes an electromagnet and is typically received within an annular cavity defined by the rotor. The rotor is configured to rotate relative to the stator about a central axis. The hub is configured to rotate about the central axis. When the electromagnet is energized, it generates a magnetic field that pulls the hub into contact with the rotor. Typically the hub is drivingly coupled to the device (e.g. compressor or pump), while the rotor receives rotational input from the vehicle's engine (e.g. via an accessory belt). Frictional contact between the hub and rotor cause torque to be transferred between the hub and rotor to drive the device.
During operation, debris (e.g. dirt, sand, grit, salt, rust) and/or fluids (e.g. water, grease, refrigerant) can get into the annular cavity and between the stator and the rotor. As the rotor rotates about the stator, the debris and/or fluids can scratch or strip the surface of the rotor and stator, exposing the bare metal (e.g. steel) beneath any coated outer surfaces. The exposed, bare metal can then corrode or oxidize (e.g. rust). Buildup of debris and oxidation material can cause friction between the stator and rotor, which can result in heat buildup and reduced efficiency and lifespan of the device and the clutch.